As is known in the art, optical phased array beam steering systems have been described for steering an optical beam in accordance with electrical command signals. One such beam steerer is described in U.S. Pat. No. 5,093,740 entitled “Optical Beam Steerer Having Subaperture Addressing” issued Mar. 3, 1992, inventors Dorschner et al, U.S. Pat. No. 5,963,682 issued Oct. 5, 1999, inventors Dorschner et al., and U.S. Pat. No. 6,704,474 issued Mar. 9, 2004, inventors Dorschner et al. all assigned to the assignee of the present patent application, the entire subject matter of all such U.S. patents being incorporated herein by reference. As described therein, the beam steerer includes an array of optical phase shifters. The phase shift provided to that portion of a beam of optical energy which passes through each phase shifter is selected by an electrical control signal fed to the phase shifter. An incident beam of optical energy, as from a laser, is thereby angularly directed (i.e., deflected) in accordance with the spatially varying phase shift provided by the array of phase shifters.
While such an arrangement is effective in providing relatively small angular deflections for the incident beams, say ±5 degrees, in some applications it would be desirable to deflect the incident beam by larger angles, say in the order of ±50 degrees.